One of the largest problems facing our society today is the growing accumulation of hazardous waste. Private industry as well as government agencies are under strict compliance to the Resource Conservation and Recovery Act and Regulations. Processes are needed which can reduce or eliminate hazardous waste on site.
Biodegradation through the use of microorganisms is one option which has great potential for reducing stock piles of hazardous waste as well as lowering toxicity.
Organisms reduce the effects of toxic materials through detoxification mechanisms. The classic case of such an enzymatic system in aquatic organisms are the phylogenetically wide spread glutathione S-transferases. These enzymes have the ability to conjugate and subsequently detoxify a wide variety of substrates. Reference is made to J. Stenersen and N. Oien, Comp. Biochem. Physiol., Vol. 69, 1981, pp. 243-252; Y. C., Awasthi, D. D. Dao, and R. P. Saneto, Biochem. J., Vol. 191, 1980 pp. 1-10; W. B. Jakoby, W. B., Adv. Enzymol, Vol. 46, 1978, pp. 383-414; and G. A. LeBlanc, and B. J. Cochrane, Comp. Biochem. Physiol., Vol. 82C, 1985, pp. 37-42.
Monoxygenase systems are responsible for the biotransformation of a variety of compounds. (Lech, J. J. and Vodicnik, M. J., Fundamentals of Aquatic Toxicology, Eds. Rand, G. M. and Petrocelli, S. R., Hemisphere Publishing Corporation, New York, 1985, pp. 526-557). A wide range of microbes degrade a variety of xenobiotics both aerobically and anaerobically.
The exploitation of microbial and molecular biology for the clean up of hazardous wastes has been extensively discussed. Reference is made to G. S. Omen and A. Hollaender, Genetic Control of Environmental Pollutants, Plenum Press, New York, pp. 408, 1984; and G. S. Omen, Environmental Biotechnology: Reducing Risks from Environmental Chemicals through Biotechnology, Plenum Press, New York, 1988, pp. 505. Some success has been realized in the biorestoration of aquifers contaminated with organic compounds as disclosed by M. D. Lee, J. M. Thomas, R. C. Borden, P. B. Bedient, C. H. Ward and J. T. Wilson, in Critical Reviews in Environmental Control, Vol. 18, 1988, pp. 29-89. Currently, a great deal of research is being conducted into optimizing conditions for biodegradation in bioreactors and in situ. Reference is made to M. A. Bianchi, R. J. Portier, K. Fujisaki, C. B. Henry, P. H. Templet and J. E. Matthews, Aquatic Toxicology and Hazard Assessment, 10 Volume, ASTM STP 971. W. J. Adams, G. A. Chapman and W. G. Landis, Eds. American Society for Testing and Materials, 1988, pp. 503-527. Pentachlorophenol removal from soil and groundwater using both a Flavobacterium strain and adapted consortia has been disclosed. (R. L. Crawford and W. W. Mohn, Enzyme Microb. Technol., Vol. 7, 1985, pp. 617-620; E. J. Brown, J. J. Pignatello, M. M. Martinson and R. L. Crawford, Appl. and Environmental Microbiology, Vol. 52, 1986, pp. 92-97; D. L. Saber and R. L. Crawford, Appl. and Environmental Microbiology, Vol. 1985, pp. 1512-1518; and J. G. Steiert and R. L. Crawford, Trends in Biotechnology, Vol. 3, 1985, pp. 300-305). These developments are critical to the way aquatic toxicologists view the effects and fate of xenobiotics and the techniques for restoration of contaminated sites.
Members of the genus Alcaligenes have been isolated from both terrestrial and aquatic environments. There have been cases of Alcaligenes being isolated from various human body fluids such as blood, urine, and spine (K. Kerster and J. DeLey, Bergey's Manual of Systematic Bacteriology, Vol. 1, Eds. N. E. Krieg and J. G. Holt, Williams and Wilkins, Baltimore, Md., 1984, pp. 361-373). Apparently the genus of gram negative bacteria is widespread and versatile in xenobiotic metabolism.
Alcaligenes strains have been reported for use to degrade various organic materials. A marine strain of Alcaligenes has been reported to degrade biphenyl and methylbyphenyl components of crude oil, but not n-alkanes. Reference is made to P. M. Fedorak and W. S. Westlake, Can. J. Microbiol., Vol. 29, 1983, pp. 497-503. However, Alcaligenes odorans DSM 30033 has been reported to degrade indole and related ringed organics. Reference is made to G. Claus and H. J. Kutzer, System Appl. Microbiol., Vol. 4, 1983, pp. 169-180. Polychlorinated biphenyl has been reported to be degraded by Alcaligenes strain Y42 in K. Furukawa, F. Matsumura and K. Tonomura, Agric. Biol. Chem., Vol. 42, 1978, pp. 543-548. The PCB, .sup.14 D-2,5,2'-trichlorobiphenyl, was absorbed into the cell surface and then gradually metabolized. Meta cleavage products were reported using thin layer chromatography, however neither .sup.14 C-metabolites nor .sup.14 CO.sub.2 was observed. Anaerobic benzoate catabolism for Alcaligenes is mediated by the plasmid pCBI as disclosed by C. K. Blake and G. D. Hegeman, J. Bacteriology, Vol. 169, 1987, pp. 4878-4883. The plasmid is 17.4 kbp and is self transmissible to Psuedomonas species. Another plasmid, pJP4, confers upon its host Alcaligenes eutrophus JMP134(pJP4) the ability to use 3-chlorobenzoate or 2,4-dichlorophenoxyacetic acid (2,4-D) as sole carbon sources. Reference is made to R. H. Don, A. J. Weightman, H. J. Knackmuss and K. N. Timmis, J. Bacteriology, Vol. 161, 1985, pp. 85-90. Plasmid pJP4 is 75 kbp in size and contains five genes coding for the catabolic pathways.
1,4-dibenz-oxazepine is a material which is useful for riot control. However, it is extremely recalcitrant to degradation, and is highly toxic to several aquatic organisms. The degradation of 1,4-dibenz-oxazepine and related compounds both in a bioreactor and in situ is desirable.